Structure elucidation and antioxidant activity of (-)-isosilandrin isolated from Silybum marianum L

A regioisomer of the known flavanolignan (-)-silandrin (3a), named (-)-isosilandrin (8a), was isolated from the fruits of a white-flowered variant of Silybum marianum L. populated in Hungary. Its structure was established both by spectroscopic methods and total synthesis, and its absolute configuration was determined by means of circular dichroism. This compound showed stronger inhibitory activity on the superoxide anion (O2*-) release by human polymorphonuclear leukocytes (PMNL) than (+)-silybin (1a,b).     

Double-joint PCR: a PCR-based molecular tool for gene manipulations in filamentous fungi

Gene replacement via homologous double crossover in filamentous fungi requires relatively long (preferentially >0.5 kb) flanking regions of the target gene. For this reason, gene replacement cassettes are usually constructed through multiple cloning steps. To facilitate gene function studies in filamentous fungi avoiding tedious cloning steps, we have developed a PCR-assisted DNA assembly procedure and applied it to delete genes in filamentous fungi. While the principle of this procedure is essentially the same as other recently reported PCR-based tools, our technique has been effectively used to delete 31 genes in three fungal species. Moreover, this PCR-based method was used to fuse more than 10 genes to a controllable promoter. In this report, a detailed protocol for this easy to follow procedure and examples of genes deleted or over-expressed are presented. In conjunction with the availability of genome sequences, the application of this technique should facilitate functional characterization of genes in filamentous fungi. To stream line the analysis of the transformants a relatively simple procedure for genomic DNA or total RNA isolation achieving approximately 100 samples/person/day is also presented.     

Etest for assessing the susceptibility of filamentous fungi

The purpose of this study was to evaluate the Etest as an in vitro antifungal susceptibility test method for different moulds originating from human samples and from the environment. A total of 50 isolates (1 Acremonium, 18 Aspergillus, 2 Cladosporium, 1 Epicoccum, 15 Penicillium, 2 Scopulariopsis and 11 Trichoderma strains) were tested by the Etest. Forty-six of the tested moulds (92%) were resistant to fluconazole with minimal inhibitory concentrations (MICs) > or = 256 microg ml(-1). There were strains resistant to ketoconazole among Aspergillus niger, A. ochraceus and Cladosporium spp. with MICs > 32 microg ml(-1). For fluconazole, no differences were observed using two different inocula, while for itraconazole, ketoconazole and amphotericin B, a 1 or less step 2-fold dilution difference in MIC was seen for the most of 10 selected strains. The MICs of fluconazole and amphotericin B obtained for Trichoderma strains by the Etest and the agar dilution method were also compared. MICs for fluconazole were in agreement, while MICs for amphotericin B were higher with 1 or 2 steps of 2-fold dilutions for most of Trichoderma strains in the case of the agar dilution method.     

Electrophoretic karyotypes of some related Mucor species

Contour clamped homogeneous electric field (CHEF) gel electrophoresis was used to obtain electrophoretic karyotypes from nine Mucorstrains representing five different species (M. bainieri, M. circinelloides, M. mucedo, M. plumbeus and M. racemosus). The chromosomal banding patterns revealed high variability among the isolates. The sizes of the DNA in the Mucor chromosomes were estimated to be between 2.5 and 8.7 Mb. The total genome sizes were calculated to be between 30.0 and 44.7 Mb. The applicability of these electrophoretic karyotypes for the investigation of genome structure, for strain identification and for species delimitation is considered.     

Preoperative lymphoscintigraphy guided sentinel lymph node biopsy in malignant melanoma

The authors present preliminary experience with preoperative sentinel lymph node biopsy carried out with lymphoscintigraphy in patients with malignant melanoma. PATIENTS AND METHODS: In the present study patients operated for primary cutaneous malignant melanoma of moderate and high severity were included. On the day of surgery isotope labelled colloid was injected intradermally around the tumor to indicate the lymphatics and to obtain basic information about the localization of the sentinel lymph node(s).During surgery the lymph node(s) previously visualized by the injection of patent-blue staining were detected with the aid of a gamma probe. Simultaneously, the excision of the primary tumor was extended. Histologically verified metastasis in the surgically removed lymph node(s) necessitated block dissection possibly within two weeks. RESULTS: The distribution of patients (19) according to tumor localisation: 2 - upper extremities; 9 - lower extremities; 2 - sacral region; 6 - trunk. Tumor thickness ranged from <1.5 mm (6 patients) to 1.5-3 mm (5 patients) and to >3 mm (8 patients). In two cases the identification of the lymph node has failed. Positive sentinel ymph nodes were detected in two patients. It is noteworthy that with one patient the sentinel lymph node was not regional but intransit. This study was aimed at the development of a suitable method. Further on we wish to try it in prospective randomized studies.